1. Field of the Invention
The present invention relates to a data carrier loader and associated loading method.
2. Background of the Invention
A variety of storage media for recording and storing data, such as magnetic tapes and optical disks are known. Using these types of recording media, however, because the capacity is finite, the amount of data that can be stored on them is also limited. In a computer system or data retrieval system in which a large amount of data must be stored, in order to include all the required data, a large number of storage media are required. Additionally, in order to retrieve data from a data carrier, it is necessary to insert this storage medium into a data reading apparatus such as a tape drive unit. In a system that requires a large number of storage media, it is troublesome to have to manually and continuously insert the storage media into and remove the media from the reading apparatus. Because of this, in many such systems a data carrier magazine, which has a plurality of storage media is used, this magazine being installed in the apparatus having the reading apparatus. Having done this, a selected medium is automatically removed from the magazine, and automatically inserted into the reading apparatus, at which data is read from the medium or new data is written thereonto, after which the medium is automatically removed from the reading apparatus and stored within the magazine. The overall unit that includes the magazine, the data reading apparatus, and the automatic mechanism that removes the storage medium from the magazine, inserts it into the reading apparatus, removes it from the reading apparatus, and then stores it in the magazine is generally called a loader.
There are a number of types of known loaders, one example being a type in which both the magazine and the reading apparatus are disposed at fixed positions, an xe2x80x9celevatorxe2x80x9d or other type of data carrier movement mechanism being used to move a selected storage medium from the magazine to and insert the storage medium into the reading apparatus. This type of loader is described below, with reference to FIG. 3 and FIG. 4 of the accompanying drawings.
FIG. 3 is a cross-section view of the loader, FIG. 4 is a cross-section view of a mechanism moving an accessor 7 of the movement mechanism up and down, and FIG. 5 is a side view of the mechanism of FIG. 4.
The loader 1 shown in FIG. 3 has, within a casing 2, a data reading apparatus 3 and a magazine 4, capable of accommodating three recording media 5, such as magnetic disk cartridges, this magazine being fixed. Additionally, as shown in FIG. 3, there is a transfer mechanism for transferring a recording medium 5 between the magazine 4 and the data reading apparatus 3. This transfer mechanism has a picker 6, which moves in the directions indicated by the arrow A in FIG. 3, so as to remove a recording medium 5 from the magazine 4 and the data reading apparatus 3, and an accessor 7, onto which the picker 6 rests, for moving the recording medium 5 up and down (in the directions indicated by the arrow B) between the magazine 4 and the data reading apparatus 3. FIG. 3 shows that the recording medium 5 is pulled out from the magazine by the picker 6, moved to the data reading apparatus 3 by the accessor 7, and inserted into the data reading apparatus 3, the picker 6 then returning. FIG. 3 further shows that after data reading by the data reading apparatus 3 is completed, the picker 6 removes the recording medium 5 from the data reading apparatus 3, and the accessor 7 returns the recording medium 5 to storage position 51 of the magazine 4.
FIG. 4 shows an accessor movement plate 9 for moving the accessor 7 up and down (in the direction of the arrow B), a drive motor 11 having a gear 12 for moving the accessor movement plate 9 in the direction of the C, and a sensor 10 for detecting the position of the accessor movement plate 9. The accessor movement plate 9 is provided with a staircase-shaped cutout hole 9 as shown in FIG. 4, into which a protrusion 71 of the accessor 7, as shown in FIG. 5, is inserted. The accessor 7 is mounted to cylindrical shafts 13 and can move freely up and down. Thus, when the accessor movement plate 9 moves, the accessor 7 moves up and down. The flat surfaces of the hole 91 are provided so as to stop the accessor 7 at positions at which the picker 6 pulls out a recording medium 6. Slits 92 are provided at positions corresponding to these flat parts of the accessor movement plate 9, these slits being detected by the sensor 10 to enable verification of the position of the accessor 7.
In the prior art, however, there is the problem that the apparatus becomes excessively large. Specifically, because to ensure smooth movement of the accessor 7 when the accessor movement plate 9 is moved, it is not possible to make the inclined parts of the staircase shaped cutout hole 91 excessively sharp, it is not possible to make the size of the movement plate 9 small. Additionally, with an increase in the number of recording media, the movement plate 9 becomes commensurately large, and it is also necessary to provide sufficient space for the movement plate 9 to move, these problems presenting a great hindrance to the achievement of a compact loader design.
FIG. 6 shows an automatic loader as disclosed in Japanese Unexamined Utility model Publication (KOKAI) No. 6-84542, in which the reference numeral 33 denotes a housing apparatus that has a housing part 32 for housing a CD, 36 is a carriage for transporting a CD 31, this carriage being moved in the vertical direction by a drive motor 37, 38 is a drive gear fixed to the shaft of the motor 37, which meshes with the drive part 44 of the carriage 36, and 3A to 3C are guide rollers for supporting the carriage 36 within the housing part 32. This automatic loader, however, does not disclose the present invention.
Accordingly, in consideration of the above-noted drawbacks in the prior art, it is an object of the present invention to provide a novel data carrier loader and loading method which improve on the drawbacks of prior art, by enabling the achievement of a compact loader design.
In order to achieve the above-noted object, the present invention has the following basic technical constitution.
Specifically, the first aspect of the present invention is a data carrier loader for moving a recording medium such as a magnetic tape cartridge from a first position to a second position, the data carrier loader comprising, an accessor for holding and moving a recording medium from the first position to the second position and vice versa, a protrusion provided on the accessor, a guide member for guiding movement of the accessor from the first position to the second position, a rotatable screw shaft on which is formed a helical groove, with which the protrusion engages.
In the second aspect of the present invention, a plurality of portions for positioning the accessor are provided on the helical groove.
In the third aspect of the present invention, a plurality of flat portions with no inclination used for positioning the accessor, are provided on the helical groove.
In the fourth aspect of the present invention, a rotation detecting means for detecting the number of rotations of said screw shaft, is integrally provided on an end portion of said screw shaft.
In the fifth aspect of the present invention, the guide member comprises a cylindrical guide shaft.
A data carrier loader according to the present invention is intended for use in loading a recording medium such as a magnetic tape cartridge, and has within the casing thereof a data reading apparatus (which can also be used for writing data onto the recording medium), and a magazine, in which at least two recording media are held, and a transfer mechanism which transfers a recording medium between a magazine and the data reading apparatus. The transfer mechanism has a picker for removing the recording medium from the magazine and from the data reading apparatus, and for inserting the recording medium to the magazine and to the data reading apparatus, and an accessor for moving the recording medium between the magazine and the data reading apparatus, the picker being placed on the accessor. The accessor is driven by drive motor via a rotating screw shaft, this screw shaft being a cylindrical bar with a helical groove formed on the surface thereof, the groove having a plurality of flat portions which, when a recording medium is to be removed or inserted, provides precise positioning of the picker. The accessor is moved by rotation of the screw shaft. The accessor is provided with an adjacent sensor for detecting the rotation of the screw shaft, the screw shaft having a counter for counting the number of rotations of the shaft using this sensor.